Conveyor chains are known in the art and include a plurality of link pins which connect a plurality of center links and side links to form a continuous conveyor chain for conveying conveyor trolleys or the like along a conveying path. As the chain is moved along the conveying path, the links and sections of the chain undergo bends and turns along a continuous conveying path or chain loop. As a section of chain bends, the pins may rotate within the openings in the center links and/or side links, which results in wear on both the pins and the center links and/or side links. The wear leads to an increase in the effective length of the chain or section of chain as well as a change in the pitch of the chain as gaps then may occur between the pins and links. It is generally undesirable to allow excessive wear in the chain, since this results in slack in the chain and/or a change in chain pitch and/or a change in the distance between products being processed, or may further result in noise and further wear or weakening of the chain. Typically, when the wear results in an increase in length of approximately 4-6 inches in a length of a 10-foot section of chain, the chain must be replaced.
Typically, the length of a chain or section of chain is measured between the ends of the center links of successive sections of chain. The length of a section of chain may be determined by detecting the leading ends of consecutive center links and knowing the speed of the chain along the conveying path. The speed of the chain and the time between detections may then be used to calculate the distance or length of the section of chain. This length may be monitored to approximate the wear in the pins and/or links of the sections of chain. However, the center links are typically forged members and may have variable lengths due to the manufacturing tolerances of the center links and surface irregularities of the links. This may result in a high variability in the measured length of the chain links or sections of chain.
Therefore, there is a need in the art for an improved system for monitoring or determining the wear of sections of chain which overcomes the shortcomings of the prior art systems or devices.